Functional Finishing of TPU Fabricated Components Based on Selective Laser Sintering

ABSTRACT The combination of selective laser sintering (SLS) 3D printing technology and thermoplastic polyurethane (TPU) demonstrates advantages in complex structure formation and flexible regulation, enabling lightweight, highly elastic, and functionally graded designs applicable to smart wearables, automotive industries, and beyond. To meet the demand for multifunctional product integration, the functional finishing of 3D‐printed components is particularly crucial. In this study, we employed a low‐temperature dyeing process and coating techniques using SLS‐3D printed TPU as the substrate, incorporating carboxylated carbon nanotubes (CNTs), zirconium sulfate (Zr(SO 4 ) 2 ), and aluminum tannate to endow TPU with conductive and hydrophobic properties. Results indicate that with a CNTs content of 6%, Zr 4+ and Al 3+ serve as coordination interactions “bridge” between TPU and CNTs, forming conductive pathways and enhancing interfacial bonding, The electrical conductivity of Zr/Al/CNTs/TPU reached 0.274 S/m, with a static water contact angle of 136°. Additionally, it exhibits stable sensing performance: maintaining stability within a 0–600 kPa pressure range, good sensitivity (GF = 0.12) in 0–80 kPa, response and recovery times of 200 and 270 ms, respectively, and stable electrical signals after 1000 compression cycles. Furthermore, practical applications in monitoring finger and wrist movements were explored; this study offers new insights for advancing wearable device development.